Plato taught that it was impossible to make a slave of a wise man, meaning that the latter by virtue of his mental endowment would rise superior to mere physical thrall. "A wise and just man," said he, "could be as happy in a state of slavery as in a state of freedom." "Therefore it has been said that the natural abides within, the artificial without. Virtue abides in the natural. Knowledge of the action of the natural and of the artificial has its root in the natural, its development in virtue. And thus, whether in motion or at rest, whether in expansion or in contraction, there is always a reversion to the essential and to the ultimate." Those eternal principles which embody all human obligations. "What do you mean," enquired the Spirit of the River, "by the natural and the artificial?" "Horses and oxen," answered the Spirit of the Ocean, "have four feet. That is the natural. Put a halter on a horse's head, a string through a bullock's nose,--that is the artificial. "Therefore it has been said, do not let the artificial obliterate the natural; do not let will obliterate destiny; do not let virtue be sacrificed to fame. Diligently observe these precepts without fail, and thus you will revert to the divine." If man does not set himself in opposition to God, the result will be TAO. * * * * * The walrus envies the centipede; Its many legs and nimble gait. the centipede envies the snake; Which moves without legs. the snake envies the wind; Which moves far more quickly even without body. the Wind envies the eye; Which travels even without moving. the eye envies the mind; Which can comprehend the whole universe, past and present alike. The walrus said to the centipede, "I hop about on one leg, but not very successfully. How do you manage all these legs you have?" "Walrus" is of course an analogue. But for the one leg, the description given by a commentator of the creature mentioned in the text applies with significant exactitude. "I don't manage them," replied the centipede. "Have you never seen saliva? When it is ejected, the big drops are the size of pearls, the small ones like mist. They fall promiscuously on the ground and cannot be counted. And so it is that my mechanism works naturally, without my being conscious of the fact." The centipede said to the snake, "With all my legs I do not move as fast as you with none. How is that?" "One's natural mechanism," replied the snake, "is not a thing to be changed. What need have I for legs?" The snake said to the wind, "I can manage to wriggle along, but I have a form. Now you come blustering down from the north sea to bluster away to the south sea, and you seem to be without form. How is that?" "'Tis true," replied the wind, "that I bluster as you say; but any one who can point at me or kick at me, excels me. As I cannot do as much to them.